Stadium: M (CC) Round: 62 Ground: Clay
| ITF M15 Oldenzaal | 2021/08/16 10:00 | Guy Den Heijer v Noel Larwig | 6-3,6-4 |
| ITF M15 Oldenzaal | 2021/08/15 14:00 | Guy Den Heijer v Paulo Knippling | 6-3,6-4 |
| UTR Pro Tennis Series Mulheim | 2021/07/30 13:30 | Guy Den Heijer v Alexander Hoogmartens | 6-2,3-6,4-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 13:30 | Mark Wallner v Guy Den Heijer | 2-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/29 07:00 | Matthew Thomson v Guy Den Heijer | 1-6,3-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/27 09:30 | Billy Harris v Guy Den Heijer | 3-6,2-6 |
| UTR Pro Tennis Series Mulheim | 2021/07/26 11:00 | Guy Den Heijer v Tim Sandkaulen | 7-5,6-3 |
| ITF M25 Marburg | 2021/07/07 10:50 | Aleksandre Metreveli v Guy Den Heijer | 6-3,1-6,6-2 |
| ITF M15 Oldenzaal | 2021/08/16 10:00 | Aydan Gomez Osorio v Alexis Canter | 1-6,4-6 |
| ITF M15 Gdynia | 2021/08/12 14:10 | Alexis Canter v Fabian Marozsan | 4-6,2-6 |
| ITF M15 Gdynia | 2021/08/11 10:05 | Alexis Canter v Arthur Fery | 3-6,6-4,6-4 |
| ITF M15 Gdynia | 2021/08/10 08:00 | Julius Tverijonas v Alexis Canter | 2-6,2-6 |
| ITF M15 Gdynia | 2021/08/09 08:00 | Piotr Galus v Alexis Canter | 2-6,1-6 |
| ITF M25 Guayaquil | 2021/08/03 14:30 | Bruno P Navarro v Alexis Canter | 6-2,6-3 |
| ITF M25 Portoviejo | 2021/07/27 14:30 | Alexis Canter v Andres Andrade | 6-3,2-6,3-6 |
| UK Pro League | 2021/07/13 13:00 | Alexis Canter v Lui Maxted | 6-4,4-6,2-10 |